P36.9
BillableBacterial sepsis of newborn, unspecified
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is P36.9 an HCC code?
Yes. P36.9 maps to Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock under the CMS-HCC V28 risk adjustment model (and Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for P36.9
For P36.9 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed P36.9 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
P36.9 is the ICD-10-CM diagnosis code for bacterial sepsis of newborn, unspecified. A serious blood infection in a newborn where the specific bacterial cause has not been identified. P36.9 sits in the ICD-10-CM chapter for certain conditions originating in the perinatal period (p00-p96), within the section covering infections specific to the perinatal period (p35-p39).
Under the CMS-HCC V28 risk adjustment model, P36.9 maps to Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock (HCC 2) with a community, non-dual, aged base RAF weight of 0.455. The V24 model used during the PY2024–PY2025 transition mapped P36.9 the same way and at the same RAF weight. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
Use this code only when sepsis is confirmed but no organism has been identified despite appropriate testing. Because P36.9 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for P36.9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code only when sepsis is confirmed but no organism has been identified despite appropriate testing
- •Query the provider to determine if culture results are pending or if a more specific code can be assigned
Clinical Significance
Bacterial sepsis of newborn, unspecified indicates a serious bloodstream infection where the specific bacterial organism has not been identified or culture results are pending. This condition still requires immediate empirical antibiotic therapy and intensive care management, as delays in treatment can result in rapid clinical deterioration and poor outcomes in neonates.
Documentation Requirements
- ✓Clinical evidence of bacterial sepsis syndrome
- ✓Laboratory markers consistent with sepsis
- ✓Documentation that organism unidentified
- ✓Blood cultures obtained
- ✓Empirical antibiotic therapy initiated
- ✓Gestational age and birth weight
- ✓Clinical course and treatment response
- ✓Risk factors for bacterial infection